The couple - who have children Sunday, eight, and Faith, six, together - tied the knot in 2006 and Nicole says their ''absolute commitment and kindness'' to each other, has kept their marriage strong for so long.

She told news.com.au: ''Keith and I always say that we are just so lucky to have each other. In this world, to be able to come back to that love and that strength is so nourishing and powerful.

''And I am coming up an 11-year wedding anniversary, 12 years together, and that's a big thing. And that is through absolute commitment and kindness, the desire to protect and help each other, what our relationship is.''

Nicole will turn 50 this year but she isn't planning a huge bash and just wants to spend time with her family.

She said: ''I get enough attention, so I am happy to have a small thing. I want a birthday cake, please and I would just love to be able to get into bed with my kids and my husband and snuggle. We'll order takeout and watch a movie. That is what I'll do and that for me is a great birthday.''

Meanwhile, Nicola is currently starring in 'Big Little Lies', alongside Reese Witherspoon, Shailene Woodley, Laura Dern and Zoe Kravitz and she was full of praise for her co-stars.

She said: ''I've been friends with Reese for a long time, so we didn't have to rehearse that relationship. But now I'd say that Laura is also one of my best friends. Shai is just a light, and Zoe I have known since she was little.''

The TV series examines the friendships between the women and Nicole found it easy to relate.

She said: ''I am lucky. I am one of those women who was raised by women, so I feel very comfortable with women. I have a sister, I have aunts, and I have a mum who is very strong and opinionated. I have one son and three daughters, so I have an enormous amount of female energy in my family.

''I am still best friends with my next door neighbour, Annette, and I have known her since I was three-and-a-half. We are both 49-years-old now. That's incredible and I have other friends like that. Keith is always saying, 'It's amazing that you have all these girlfriends'.''